1. Field of the Invention
The present invention is directed toward the field of replicating (or synchronizing) information folders between a host system and a mobile data communication device (“mobile device”). Specifically upon receiving this redirected information at their mobile device, the user can then organize this data into hierarchies, commonly known as folders, and may also perform various other operations on the redirected data. These organizational and other operations are then synchronized back to the original host system for replication. The invention also provides for the synchronization of a storage representation model for storing the data in a hierarchy of folders at the host system and the mobile device.
2. Description of the Related Art
Present systems and methods for replicating information from a host system to a user's mobile data communication device are typically “synchronization” systems in which the user's data items are warehoused (or stored) at the host system for an indefinite period of time and then transmitted in bulk only in response to a user request. In these types of systems and methods, when replication of the warehoused data items to the mobile device is desired, the user typically places the mobile device in an interface cradle that is electrically connected to the host system via some form of local, dedicated communication, such as a serial cable or an infrared or other type of wireless link. Alternatively, the user might have to perform a special ‘connection’ action every so often that will synchronous all the pending items required by the user, provided they remember. Software executing on the mobile data communication device then transmits commands via the local communications link or a network link to the host system to cause the host to begin transmitting the user's data items for storage in a memory bank of the mobile device. In these synchronization schemes, the mobile unit “pulls” the warehoused information from the host system in a batch each time the user desires to replicate information between the two devices. Therefore, the two systems (host and mobile) only maintain the same data items after a user-initiated command sequence that causes the mobile device to download the data items from the host system.
Another major problem with the current pull-based systems is that the user must deal with the information all over again once the user returns to his office and accesses the information store at the host system. This situation occurs because the average user can get hundreds of pieces of electronic information a day. This is very common in e-mail systems where internal company mail, and external Internet mail, merge into one common mailbox creating a multitude of sources all merged into one location. As a result, once the user returns to their office, even though they may have seen and read the mail while traveling on their mobile device, they still have to re-read the messages and then organize the information into folders based upon the content. This results in user frustration, as the mobile device has not solved the problem of saving them time when the user returns to his office and accesses the information store at the host system.
A general problem with these known synchronization systems is that the only time that the user data items are replicated between the host system and the mobile data communication device is when the user commands the mobile device to download or pull the user data from the host system. Five minutes later a new message could be sent to the user, but the user would not receive that message until the next time the user fetches the user data items. Thus, a user may fail to respond to an emergency update or message because the user only periodically synchronizes the system, such as once per day.
Other problems with these systems include: (1) the amount of data to be reconciled between the host and the mobile device can become large if the user does not “synchronize” on a daily or hourly basis, leading to bandwidth difficulties, particularly when the mobile device is communicating via a wireless packet-switched network; (2) reconciling large amounts of data, as can accrue in these batch-mode synchronization systems, can require a great deal of communication between the host and the mobile device, thus leading to a more complex, costly and energy-inefficient system; and (3) the need to deal with the information a second time once the user returns to the office and accesses the information store at the host system. A more automated, continuous, efficient and reliable system of ensuring that user data items are replicated (synchronized) at the user's mobile device is therefore needed.